U.S. patent application number 11/480764 was filed with the patent office on 2008-01-03 for system and method of identifying products enclosed in electrostatic discharge protective packaging.
Invention is credited to Horst Schwarz.
Application Number | 20080001761 11/480764 |
Document ID | / |
Family ID | 38876001 |
Filed Date | 2008-01-03 |
United States Patent
Application |
20080001761 |
Kind Code |
A1 |
Schwarz; Horst |
January 3, 2008 |
System and method of identifying products enclosed in electrostatic
discharge protective packaging
Abstract
A system and method of identifying objects packaged in
electrostatic discharge (ESD) protection packaging is disclosed.
The system includes an ESD protection package and a radio frequency
identification (RFID) tag. The RFID tag is affixed to the object
prior to being inserted into the ESD protection packaging. A RFID
interrogation device having a transmitter, an antenna and a
receiver is used to interrogate the RFID tag and output the
identification data to a display or to a computer. The method
includes affixing an RFID tag to an object prior to placement in
the ESD protection packaging, providing a RFID interrogation device
including an antenna in proximity to the packaged object, and
reading the data stored by the RFID tag for identifying the
object.
Inventors: |
Schwarz; Horst; (Forchheim,
DE) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Family ID: |
38876001 |
Appl. No.: |
11/480764 |
Filed: |
July 3, 2006 |
Current U.S.
Class: |
340/572.8 ;
340/572.7 |
Current CPC
Class: |
G06Q 10/087 20130101;
G08B 13/2462 20130101 |
Class at
Publication: |
340/572.8 ;
340/572.7 |
International
Class: |
G08B 13/14 20060101
G08B013/14 |
Claims
1. A system for identification of packaged products, comprising: a
radio frequency identification (RFID) tag affixed to, or associated
with, an object to be identified; a electrostatic discharge (ESD)
protection package; and a RFID interrogation device, wherein the
object is enclosed in the ESD protection package and the RFID
interrogation device transmits at a low radio frequency.
2. The system of claim 1, wherein the low radio frequency is
between approximately 120 kHz and approximately 150 kHz.
3. The system of claim 2, wherein the low radio frequency is one of
approximately 125 kHz or approximately 134 kHz.
4. The system of claim 1, wherein the RFID interrogation device
comprises a transmitter, an antenna and a receiver.
5. The system of claim 1, wherein the RFID interrogation device has
a data interface configured to communicate with at least one of a
computer, a telecommunications network or a visual display.
6. The system of claim 1, wherein the RFID tag is affixed to the
object by one of gluing, clamping, clipping, or tying.
7. The system of claim 1, wherein the RFID tag has one of a
read-only memory or a read/write-once memory or a read/write
memory.
8. The system of claim 4, wherein the antenna comprises two
antennas disposed such that the packaged product may be inserted
therebetween.
9. A method of identifying an object in an electrostatic discharge
(ESD) protection package, the method comprising: providing an radio
frequency identification (RFID) tag capable of storing at least
identification data associated with an object; attaching or
associating the RFID tag to the object; and inserting the object
into the ESD protection package.
10. The method of claim 9, further comprising: providing an RFID
interrogation device having a transmitter, an antenna and a
receiver; interrogating the packaged object; and at least one of
displaying the object information or transferring the object
information a computer data base.
11. The method of claim 10, wherein the transfer of object
information to a computer data base is by transmission over a
network.
12. The method of claim 11, further comprising updating an object
inventory file in the computer data base.
Description
TECHNICAL FIELD
[0001] The present application relates to a system and method of
identifying a product enclosed in electrostatic discharge (ESD)
protective packaging, and in particular to the use of
radio-frequency identification (RFID) techniques.
BACKGROUND
[0002] Modern electronic products using, for example, semiconductor
technology, are sensitive to high electric fields and currents,
even though such fields and currents may be of a transitory nature.
Degradation of performance or permanent damage to the devices is
known to commonly occur unless the devices and products are
properly protected during the course of production, storage,
shipment, installation and use. For storage and shipment, various
products, which may be termed ESD (electrostatic discharge)
protective packaging, are used to minimize the possibility of
damage. They may be used to wrap or bag the product, and may also
include containers suitable for handling during typical factory or
shipping operations.
[0003] ESD protective packaging typically has a characteristic that
the surface or volume resistivity of at least a layer thereof is
significantly lower than that exhibited by insulators which may be
typical plastics, which may also comprise part of the packaging.
The lower resistivity may be achieved, or example, by the use of
special polymers, the loading of polymers with conductive materials
such as metal or carbon, or the deposition of thin layers of metal
on plastic. Often a combination of these techniques is used to
minimize voltage build up due to triboelectric charging, or to
shield the product from high electromagnetic fields or
currents.
[0004] Identification of products and other items can be performed
by the reading of bar codes using optical means and by the use of
radio-frequency identification (RFID) to obtain information about a
product using a non-contact automated technique. Such information
may be used to sort products, inventory the products, retrieve
products from storage or similar industrial uses. In particular,
RFID is used to interrogate a device, often called a transponder or
"tag" that has been affixed to the product or the package. A
variety of different frequencies are used by RFID equipment
depending on governmental regulations and may include operation in
the LF, HF, UHF and microwave frequency ranges. LF and HF operation
in the worldwide ISM (industrial, scientific and medical)
allocations may be of an unlicensed type, with restrictions on the
power used by the interrogating devices.
[0005] Items returned to a manufacturer or distributor may have
RFID tags, and may also be protected by ESD bags or wrapping. It
would be desirable to read the RFID tag without opening the box or
container or the ESD bag in which the item was shipped.
[0006] When a passive RFID tag is used, the power required to
operate the tag is provided by the electromagnetic fields generated
and emitted by an antenna associated with the interrogation device.
As such, any excess loss of power during the transit of an
electromagnetic signal between the interrogation device and the tag
will reduce the distance over which the interrogation of the RFID
tag can be performed. Since many of the passive RFID tag systems
are effective for a range of about a meter or less under ideal
conditions, any substantial loss of signal strength may render the
entire approach inoperative.
[0007] In particular, many types of ESD packaging, having layers of
material which enclose the product and which may be conductive,
will produce a shielding effect, sometimes known as a Faraday cage,
and substantially attenuate the electric and magnetic fields of
radiated electromagnetic waves. As such, it may not be possible to
interrogate (or "read") the information on a RFID tag affixed to
the product when the product is enclosed in ESD packaging. Even
when the ESD packaging partially optically transparent, the reading
of bar codes by optical means is difficult. Bar codes on the
product would not be readable when the product in an ESD bag is
enclosed by an outer shipping container such as a cardboard
box.
SUMMARY
[0008] A system for identification of packaged products is
described, including a radio frequency identification (RFID) tag
affixed to an object to be identified; a electrostatic discharge
(ESD) protection package; and an RFID interrogation device, or RFID
reader. The object is enclosed in the ESD protection package and
the RFID interrogation device operates at a low radio
frequency.
[0009] A method of identifying an object in an electrostatic
discharge (ESD) protection package is described, the method
including: providing a radio frequency identification (RFID) tag
capable of storing at least identification data associated with an
object; attaching the RFID tag to, or associating the RFID tab
with, the object and inserting the object in the ESD protection
package. The method may further include providing a RFID
interrogation device or reader having a transmitter, an antenna and
a receiver; interrogating the packaged object; and at least one of
displaying the object information as provided by the RFID tag or
transferring the object information a computer data base.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a RFID identification tag enclosed in an ESD
bag and packaging, being read by a RFID interrogation system.
DESCRIPTION
[0011] Exemplary embodiments may be better understood with
reference to the drawings, but these examples are not intended to
be of a limiting nature. When a specific feature, structure, or
characteristic is described in connection with an example, it will
be understood that one skilled in the art may effect such feature,
structure, or characteristic in connection with other examples,
whether or not explicitly stated herein
[0012] In the interest of clarity, not all the routine features of
the implementations described herein are described. It will of
course be appreciated that in the development of any such actual
implementation, numerous implementation-specific decisions must be
made to achieve a specific goals, such as compliance with system
and business related constraints, and that these goals will vary
from one implementation to another.
[0013] The processing of a received signal may be by either analog
or digital circuits, or a combination thereof. The signal
processing may be also performed by one or more computers with
associated memory and computer code which performs mathematical
operations and functions equivalent to that performed by the analog
or digital circuits. Herein, there is not intended to be a
restriction of the type of circuit which performs each function, or
the combination of types of circuits which may be used, although
the examples may mention a specific type of circuit in the
description thereof.
[0014] Where a computer or a digital circuit is used, the received
signal may be converted from analog format to a digital
representation thereof in an analog-to-digital (A/D) converter, as
is known in the art. The A/D conversion process may be performed at
any point after reception by the antenna. The choice of location of
the A/D conversion will depend on the specific application.
[0015] Embodiments of this invention may be implemented in
hardware, firmware, software, or any combination thereof, and may
include instructions stored on a machine-readable medium, which may
be read and executed by one or more processors. Data communications
and processing modalities may include wired or wireless types, and
the protocols for communications may be exemplified by TPC/IP
transport and network layer protocols, or other standard protocols
as may now exist or may be developed. Wireless communication means
may include, audio, radio, lightwave or other technique not
requiring a physical connection between a transmitting device and a
corresponding receiving device.
[0016] Where the term "web" or "Internet" is used, the intent is to
describe an internetworking environment, including both local and
wide area networks, which may have both wired and wireless
components, where defined transmission protocols are used to
facilitate communications between diverse, possibly geographically
dispersed, entities. An example of such an environment is the
world-wide-web (WWW) and the use of the TCP/IP data packet
protocol, and the use of Ethernet or other hardware and software
protocols for some of the data paths.
[0017] A system and method of using a passive radio-frequency
identification (RFID) tag 10 to provide identification of a product
20 enclosed in an electrostatic discharge (ESD) protection package
or bag 30 is described. An RFID identification tag 10 is affixed to
each individual item of a product 20 as a step in the manufacturing
or packaging process. Alternatively, the RFID tag 10 may be
associated with the product at the time of packaging in an ESD bag
30 by at least placing an RFID tag 10 in the bag 30 with the
product 20.
[0018] The RFID tag may be of a read-only or read/write type and be
of a size and durability appropriate to the product and use
thereof. The frequency of operation of the interrogation signal is
selected to be in the low radio frequency (LF) band, typically
120-150 kHz, but higher or lower radio frequencies may be used. The
RFID tag may also have an optical bar code of any type
corresponding to at least some of the information stored in the
RFID tag, and may be verified at the time of packaging by at least
one of optical or RFID methods. In an example, the RFID tag may
respond to the interrogation signal on a frequency of about 62.5
kHz or other frequency differing from the interrogation signal
frequency, and the system may operate in a full duplex mode.
[0019] The product with the attached RFID tag may be placed into an
ESD protection bag and the bag is typically closed and may be
sealed with a tape, a sliding closure or by heat sealing. Often,
the bag is not opened again until the product is ready for use,
such as by installing as a repair part, as an upgrade to a
computer, or as part of a manufacturing operation performed after
storage, transportation, or the like.
[0020] When a LF signal is used to interrogate the RFID tag, it has
been experimentally determined, as described herein, that
sufficient electromagnetic energy penetrates the ESD protection bag
so that a useful signal is returned to the RFID sensor and that the
data stored in the RFID tag may be read. The use of higher radio
frequencies, such as high(HF)-, ultra-high(UHF)- and microwave
frequencies is known not yield useful data as the losses associated
with the conductive or partially conductive nature of the ESD
protection bag reduces the signal strength of the signal from the
RFID tag such that it cannot be usefully detected.
[0021] The penetration of a conductive material by a
electromagnetic wave is characterized by a parameter known as the
"skin depth". This depth is associated with an attenuation of the
incident signal such that the field has fallen to a factor of l/e
of the incident field. Since the electromagnetic signal must pass
through the material on the incident and reflected portions of the
path, the overall attenuation is proportional to 1/e.sup.2. The
skin depth in conductive materials is proportional to f.sup.1/2,
and thus it is expected that low frequency (LF) signals will have
greater skin depths that higher frequency signals and thus will
experience lower attenuation in penetrating the ESD protection
packaging. Where the term LF is used, it will be understood by
persons of skill in the art that the formal band limits of 30 to
300 kHz are meant only approximately, as the f.sup.1/2 dependence
of the skin depth results in a slow variation of system performance
with operating frequency. The actual operating frequencies chosen
are usually constrained by governmental regulations.
[0022] In an aspect, shown in FIG. 1, a product 20, which may be an
electronic circuit module or the like, having a RFID transponder
tag 20 affixed thereto is inserted into an ESD protective bag 30.
The bag may be further enclosed by a conventional cardboard or
plastic container 40 for physical protection during storage and
transportation, depending on the specific product and use.
[0023] A RFID interrogation device 50, comprising a transmitter and
receiver and an antenna 70 is provided, where the frequency of
operation is in the low frequency (LF) radio spectrum. The antenna
70 may be mounted in a table top (not shown), and connected to the
RFID interrogation device 50 by a cable. The RFID interrogation
device may be connected to one or more of a display, a local
computer, or a communications network 60 to use the data obtained
from the RFID tag 10.
[0024] Due to governmental regulations, the radio frequencies used
may be restricted in order to avoid interference to other
authorized users of the radio spectrum. Typically, authorized
frequencies may be 125 kHz and 134 kHz, although other LF
frequencies and possibly MF frequencies could be used if they
subsequently become authorized. The transmitted power may also be
limited in accordance with governmental regulations, which may also
include safety considerations.
[0025] The signal transmitted by the antenna 70 impinges on the ESD
protection bag 30 and a portion of the energy passes through the
ESD protection bag 30 and interacts with the RFID tag 10. The RFID
tag 10 responds by using the received energy to power the circuitry
of the RFID tag 10 so as to impose a modulation on a signal that is
radiated or reradiated by the RFID tag 10. The signal from the RFID
tag penetrates the ESD protection bag and is received by the
antenna of the interrogation device 50 and is demodulated by the
receiver portion of the interrogation device. The modulation
imposed on the signal radiated or re-radiated by the RFID tag 10
may represent data stored in the RFID tag 10 at a time prior to the
interrogation time, and may be used to identify the part number or
other attributes of the product. The other data, such as a serial
number, manufacturing date, test results, and the like may be
stored, depending on the specific use. The use of writable or
rewritable RFID tags is more expensive, and the selection of RFID
tag type may be an economic consideration.
[0026] Where a RFID tag has a read/write memory capable of multiple
write operations, all or part of the data stored on in the RFID tag
may be updated or changed.
[0027] The signal from the RFID tag received by the antenna of the
interrogator is demodulated by the receiver portion thereof, and
the resultant data may be displayed for an operator to view or use
or transferred to a computer, communications system or data
management system for further processing or storage, or to update
an inventory listing.
[0028] The RFID tag 10 may be affixed to the product, module, or
object 20 by gluing, clamping, or a loop passing through a hole in
the item and in the RFID tag 10, or similar permanent or
non-permanent means. For example, an RFID tag may be affixed to the
object by "super glue", screws or bolts, or the insertion of the
tag in a clip previously affixed to the object. The RFID tag may
also be printed with an optical bar code representing some or all
of the information contained in the RFID memory.
[0029] In an aspect, a pair of antennas 70 may be provided so that
an antenna 70 may be disposed on either side of a package for
transmitting and receiving the signals generated by the transmitter
of the RFID interrogation device 50. Such a configuration may be
effective in reading the RFID tag 10 when the tag is affixed to a
metallic object and the thickness of the metallic object is such
that increased attenuation results.
[0030] A method of identifying an item enclosed in an ESD
protective bag includes the steps of: writing identifying
information relating to an item of manufacture into the memory of a
RFID tag or providing a RFID tag having such information previously
incorporated therein; affixing the RFID tag to the item; packaging
the item in an ESD protective material; locating the packaged item
in the vicinity of a low frequency (LF) interrogation device;
reading identifying information from the RFID tag. RFID tags may be
mass produced with predetermined data that is associated with, or
is, the product description, and these RFID tags are often used as
they are less expensive than individually written RFID tags.
[0031] The method may further include displaying the identifying
information read from the RFID tag, transmitting the information to
a computer, a communications network or a data management system,
and updating an inventory file.
[0032] The operation of the system and method was demonstrated by a
series of informal tests performed under office conditions. In
actual use, the antenna may be mounted in a tabletop having an
opening cut in the top to expose the sensor antenna, and may have a
dielectric surface disposed between the antenna and the object
containing the RFID tag. The table top may be made out of a
dielectric material. In the experiments, however, the packages were
pulled or slid over the antenna surface. The goal of these
experiments was to demonstrate that a low-frequency RFID tag may be
read through an ESD bag and further external packaging. Generally,
if the ESD bag was packaged in a container or box, it was
determined that the box may have to be reoriented or flipped by 180
degrees in order to bring the RFID tag into closer proximity with
the antenna in order for the tag to be read. Electronic circuit
cards and a metal sheet were used as examples of products which may
be packaged as described herein.
[0033] The ESD bags used were made of "topshield" static shielding
material obtained from Strobel GmbH (Langenzenn, Germany) and are a
laminate with, in order, anti-static, polyester, metal,
polyethelene, and anti-static layers. The overall thickness was 2.9
mil. The metal layer had a surface resistivity of less than 100
ohms. The RFID tags used were glass-encapsulated read-only devices
having a diameter of 2.12 mm and a length of 12 mm (part number
ID102/2, obtained form AEG Identifikationssysteme GmbH, Ulm,
Germany); the RFID tag reader was a model ARE 12/RS232 (obtained
form AEG Identifikationssysteme GmbH, Ulm, Germany) and the antenna
was a model AAN X2F (obtained form AEG Identifikationssysteme GmbH,
Ulm, Germany).
[0034] A RFID transponder tag 10 was selected and test read by
bringing the transponder into proximity with the antenna of the
RFID interrogation device, and the ID number and the interrogation
data recorded. A variety of typical electronic circuit cards were
tested by affixing a RFID tag 10 thereto with cellophane tape or
"super glue"; at least one of the samples was a metal sheet. The
reading of data from the RFID tag was verified after this step in a
manner similar to the first reading. The circuit cards, as examples
of products, were introduced into ESD bags and the bags were
closed, including folding the bags several times, and the folded
bags were placed inside of cardboard boxes. Each of the samples was
bought into proximity of the antenna 70 and reoriented if necessary
to achieve a successful reading. The reading was repeated numerous
times to verify successful performance. In the case of the metal
sheet, it was sometimes found necessary reorient the sample by 180
degrees so that the shielding effect of the thick metal was
mitigated. This was also sometimes necessary with the printed
circuit boards as well.
[0035] Although only a few exemplary embodiments of this invention
have been described in detail above, those skilled in the art will
readily appreciate that many modifications are possible in the
exemplary embodiments without materially departing from the novel
teachings and advantages of the invention. Accordingly, all such
modifications are intended to be included within the scope of this
invention as defined in the following claims.
* * * * *